How is the zakat calculated for 19 grams of saved gold from 2010 to 2021, knowing that no zakat was paid on it due to the belief that it was not obligatory, and with the intention of saving it for the future, and it has now been sold to purchase medical equipment after settling the husband's debts?

Zakat is obligatory on hoarded gold if it reaches the nisab and a full lunar year has passed over it. The nisab is 85 grams of pure gold (24 karat). If the gold alone does not reach the nisab, but the owner possesses other money, and the total of the gold and money reaches the nisab, then zakat becomes obligatory on the entire amount after a year has passed since the combined wealth reached the nisab. The amount of zakat is a quarter of a tenth (2.5%) of the total wealth.